One method of removing desirable minerals from waste materials in an ore is to reduce the raw size of the ore. U.S. Pat. No. 3,887,141 teaches a mill for the reduction of ore that uses an impact rotor for obtaining the first reduction. Initially, the material to be reduced in size is introduced into the swept area of the rotor. When the material contacts the rotor, a portion of the accumulated kinetic energy generated by the rotor is transferred to the material, forcing it to accelerate as well as change direction. The material will tend to resist this, so the energy transferred accumulates within the material. This in turn will cause any friable material to shatter along its natural fault lines and the resulting smaller particles will be accelerated away from the rotor. These smaller particles are directed into a series of shatter bars mounted on the walls of the primary reduction chamber, which cause further reductions in the size of the particles upon impact. In theory, airflow from the rotor is supposed to carry sufficiently reduced particles into a secondary reduction chamber wherein they are reduced to fine particles and then collected at a fine particle outlet. However, during operation, material tends to pack in the bottom of the primary reduction chamber, clogging the apparatus. U.S. Pat. No. 4,037,796 teaches a modified version of the ore milling apparatus including a fluidizing rotor located in the base of the primary reduction chamber. This second rotor is supposed to slow the rate at which material settles into the base of the primary reduction chamber by improving the flow of the articles. However, this fluidizing rotor does not compensate for other flaws in the apparatus. Specifically, there is also a tendency for fine particles to collect within the apparatus in areas of low air pressure, as the airflow generated from the rotor is insufficient to carry all of the particles to the outlet. As these particles are naturally quite abrasive, considerable wear will occur in these areas. One area of low pressure, due to its proximity to the outlet, is the secondary reduction chamber. Over time, particles accumulate to such an extent so as to block access to the fine particle outlet. In addition, as weight is the only determining factor in this apparatus as to whether or not the particle passes on to the secondary reduction chamber and the fine particle outlet, the possibility exists that a particle of sufficient size could become lodged in this region of the apparatus. Clearly, this apparatus has the disadvantages of incurring considerable wear during operation and requiring frequent maintenance and cleaning.